Why Hyperclay Local

Hyperclay Local exists so your malleable documents can live as plain .html and .htmlclay files on your computer, save their own changes to disk, and sync with hyperclay.com when you want them to.

A file that remembers#

An HTML file can lay out an interface, run JavaScript, and respond to every click and keystroke. Opened directly from disk, however, the browser sandbox blocks the page from writing its changes back to the file. Close the tab and every edit is gone.

Hyperclay Local runs a small local server on your computer with a save endpoint (POST /_/save; see How it works and Saving and stale-write protection). When you edit a document in the workspace window or in your browser, the page serializes its updated DOM and posts it to the local server, which writes the file to disk and keeps the previous version in .hyperclay/versions/ as a backup.

Because the interface, logic, and data all live inside that single HTML file, the file itself is the complete document. You can inspect it with View Source, open it in any text editor, commit it to Git, back it up with your regular backup tools, or export it as a zip with its attachments (see Export as zip).

Compared to static files, localStorage, and a backend#

• A static file cannot save itself: opening an .html file over file:// loses every edit on refresh. Hyperclay Local serves the folder on localhost so the document can save its changes back to disk.
• localStorage traps data inside one browser: data stored in localStorage or IndexedDB stays locked inside a single browser profile, separate from the HTML file, and disappears if browser storage is cleared. In a malleable document, the data is stored in the HTML file on disk.
• No backend or build step to maintain: you do not need to run a database, configure a bundler, or manage a remote server to use your own documents. Even Tailwind CSS compiles automatically on save when a document links /tailwindcss/<name>.css.

Local first, synced when you want#

Everything in Hyperclay Local works offline with no account required (see Offline behavior and privacy):

• Your personal folder and team folders are regular folders inside your home directory.
• Every save keeps a local version backup on disk (see Recover from backups).
• Scripts and command-line tools on your machine can read and update documents through the JSON data API or edit sections in place with AI editing.
• Local editing sends no analytics or telemetry; the only background network request when sync is off is the periodic update check (see Updates).

When you want to publish a document on the web, share it, or work with a team on hyperclay.com, you can connect a sync key and turn on Sync with hyperclay.com. Sync is off by default, your sync key is encrypted with your operating system’s credential store, and your local folders keep serving and saving even when sync is paused, disconnected, or offline.

Core principles#

• Own your stack: No vendor lock-in. Keep your documents as plain files on your computer and run them anywhere.
• Malleable: Your HTML documents modify themselves in the browser and save changes straight to disk.
• Shareable: When synced with hyperclay.com, send a link so others can view, edit, or clone your document.
• Standard web platform: Built on standard HTML, CSS, and JavaScript with ClayJS, with no proprietary framework required.